Relief valve



Petented Apr. 27, 1943 UNITED STATES PATENT OFFICE RELIEF VALVE WilliamH. m and Roy L. Simpson,

Kansas City, Mo. Application March 18, 1940, Serial No. 324,514

scams. (01. 137-53) This invention relates to pressure relief valves Iinvention to provide a relief valve .which is capable of operating atlow pressure differentials and whereby a predetermined maximum pressureis maintained within a vessel. i

Other objects of the invention are to provide a. low pressure reliefvalve of simple and inexpensive construction; to provide a low pressurerelief valve which is also adapted to actuate in response to vacuumpressures acting within a vessel as in case of sudden condensation ofcon tained vapor or emptying the contents thereof; to provide a reliefvalve construction wherein the valving member seats uniformly about theperiphery of the valve; and to provide for positive seating of thevalving member responsive to pressure acting in the vessel.

In accomplishing these and other objects of the invention, ashereinafter pointed -out, we have provided improved structure, thepreferred forms of which are illustrated in the accompanying drawings,wherein:

Fig. 1 is a vertical section through a pressure relief valve constructedin accordance with the present invention.

Fig. 2 is an elevational view of the valve, part of which is shown invertical section at righ angles to the section shown in Fig. 1.

Fig. 3 is a plan view or the valve, parts of which are broken away tobetter illustrate the construction thereof.

Fig. 4 is a vertical section through one side of the valve showing thevalve in position for re lieving pressure.

Fig. 5 is a similar section but showing the valving member unseatedresponsive to vacuum modified form of the invention, showing itsadaptability to a thief hatch cover.

Referring more in detail to the drawings, and

' 1 to 5 inclusive:

first t the form of the invention shown in Figs.

annular wall 3 terminating at its lower edge in aflange 4 that isthreaded orotherwise suitably formed for attachment to a nipple or otherconnection with a vessel on which the release valve is installed. Theupper portion of the wall 3 terminates in an outwardly flaring portion 6having an upstanding annular rib 'l'forming a circular seat 8 encirclingthe'. relief outlet opening through the valve body.

Bridging the wall 3 within the interior of the body 2 is a spider-likesupport 9 having a central. sleeve l0 provided with an opening llcoaxial with the seat 8. The opening ll ispreferably provided with abushing I2 in which is The cap I4 is shown as including atop l5 havingan annularly depending wall 16 spaced outwardly from the seat 8 andterminating in an outwardly ofiset portion H to form a downwardly facingannular shoulder l8. Depending from the center of the .top [5 is aninternally threaded socket 19 receiving the threaded end of a stud 20forming the core of the stem 83. The stud 2B is locked from rotationrelatively to the cap I by a jam-nut 2|which engages the end of thesocket. The stud extendsthrough a sleeve 22 which spaces washers 23 and24 also sleeved on the stud to-form stops relativelyengageable with theuper and lower ends of the sleeve Ill tolimit movement of the cap to andfrom the body member2.

'The washer 23, is preferably faced with a resillent washer 25 to abutthe upper end of the sleeve Ill. The washer 23, sleeve 22, and washer 24are retained in rigid assembly against the jamnut 2| by a nut 26threaded on the dependingend of the stud, as shown in Fig. 1.

The spacing sleeve 22 is of sufl'icient lengith to allow ample movementof the cap from the body member to give ample flow passage for therelief of pressure, as later described.

Seated against the shoulder I8 is the outer marginal edge 21 of aflexible valving member in the form of .a ring 28, which is ofsufiicient width to bridge the spacing between the seat 8 and the walliii of the cap flange so that its inner marginal edge 29 overlaps theseat 8 as clearly shown in Fig. 1. The valving ring 28 is retainedagainst the shoulder I8 by the outer rim 30 of a grid-like support 3!,having an inner rim 32 loosely encircling the rib 7. The rim 3: isofiset downwardly with respect to the rim and is connected therewith byspaced arms 33 which form support for the flexible valving ring andprevent sagging thereof under pressure acting from within the cap. Thegrid-likesupporting ring 3| is retained in clamping contact with theouter marginal edge 2'5 of the valving member by an expansion ring 341received in a locking groove 35 formed in the inner face of the offsetportion Id of the cap flange. With this arrangement the outer portion ofthe valving ring is anchored to the cap and the inner marginal edgeengages the seat 8 and is retained in sealing contact therewith bypressure from the vessel acting through the nipple 5.

The cap I 4 is of suflicient weight, or weighted by a plurality of disks36, so that it normally remains seated with the washers 23 and 25resting upon the spider sleeve Iii, a suiiicient number of disks 36being applied to maintain a predetermined pressure within the vesselbefore the pressure is sumcient to lift the cap and effect unseating ofthe valving ring from the seat 8. The

disks 36 are preferably retained on the cap by cap-screws 31 havingtheir shanks extending through openings 38 in .the disks and intothreaded sockets 39 formed in the top I5 of the cap. After applicationof the required number of disks, the screws may be sealed by a wire toindicate unauthorized tampering therewith.

In order to assure seating of the valving ring on the seat 8, thevalving ring 28 supports a.

, the cap wall l6.

Extending outwardly from offset sides of the wall 3 are bosses 46 and 41having threaded openings 48 therein to receive the threaded shanks d9 oftrunnions 50. The trunnions 50 form pivots for hearing sleeves 5| and 52on a yoke-like actuating lever 53. Extending from one of the bearingsleeves is a cam-like lug 54 that is adapted to engage under the rim 32to raise the cap and effect unseating of the valving ring when the lever53 is manually operated. The lever 53 is normally retained in retractedposition by a coil spring 55 sleeved on one of the trunnion shanks andhaving one end 56 fixed to the lever and its opposite end 51 engaged ina socket formed in the end of the boss 41. Movement of the! leverresponsive to action of the spring is limited by a lug 58 engagingagainst a lug 59 projecting from the outer face of the wall 3 as shownin Fig. 2.

Assuming that the relief valve constructed as described is mounted on avessel for containing liquids under a predetermined pressure, thevalving ring willremain engaged with the seat 8 responsive to thepressure acting on the upper face of the ring. The valving ring is,therefore, uniformly pressed against the seat about its entire peripheryso as to prevent leakage thereunder. When the pressure begins to exceedthe predetermined pressure, the pressure acts against the cap and sincethe cap is of larger area than the effective area of the valving ring,the cap is lifted by the excess pressure so that the valving ring israised from its seat and the excessive pressure is vented between thevalving ring and seat as shown in Fig. 4. when the pressure is reducedto the predetermined maximum, the cap settles to its original position,again seating the valving ring and preventing further discharge from thevessel. Should a vacuum occur in the vessel responsive to suddencondensation of contained gases, or upon emptying the contents of thevessel, the external air pressure, acting on the under side of thevalving ring, effects unseating thereof against weight ring 4| so thatthe air may enter the tank and prevent collapse thereof. When the vacuumis relieved, the weight 4! is again effective in restoring the valvingring on its seat so that the predetermined pressure may be again builtup within the vessel.

The 'form of the invention shown in Fig. 6 is the same as that justdescribed with the exception of the cap 60. In this instance the top 6|of the cap substantially conform to the diameter of the seat 62 on thebody member 63 and the side flange 64 thereof terminates in a laterallyextending annular flange 65 to space a. depending rim 66 thereof asuflicient distance from the seat to accommodate the valving ring 61.The under faceof the flange 65, except forthe clamping portion 68, isrelieved as at 69 to permit pressure within a vessel to act on the upperface of the valving ring. The valving ring is retained in clampingcontact with the shoulder by an expansion ring l0 inset within a groovell formed in the inner face of the rim 66. In thisconstruction the undersupport for the valving ring is eliminated. I

The operation of the device just described is the same as that of thepreferred form.

In Fig. 7 we have shown the invention asincorporated ina thief hatch,the thief hatch including a collar-like'body 12 having a footing flange13 adapted for attachment to the roof of a vessel. The upper portion ofthe collar terminates in a seat 14 for seating a hatch cover I5. Thehatchcover 15 includes a closure plate 16 of a larger diameter than theseat 14 so that the outer marginal edge of a valving ring 11 maybeattached to the under side of the cover in outwardly spaced relationwith the seat I4. In the illustrated instance the valving ring 11 issecured by a clamping ring 18 retained in clamping engagement with thevalving ring by,

screws 19 having threaded shanks extending through openings 8| in therings 18 and 82 in the valving ring 11 and into threaded sockets 83 ofthe cover as shown in Fig. 7. The inner portion of the valving ring isof reduced thickness so that it is completely flexible to engage theseat 14 and provide space 84 under the cover to allow pressure to actupon the valving ring until such a time that the pressure is sumcient toprevent leakage of the pressure below a predetermined maximum. However,should the pres sure exceed the predetermined maximum, thecap of therelief valve is lifted thereby to effect unseatlng of the valving ringagainst the pressure acting thereon. It is also obvious that the valvingrings in the forms of the devices shown in Figs. 1 to 6 inclusive serveto relieve vacuum Patent is:

1. A relief valve of the character described,

including a valve body having a circumferential seat encircling a reliefopening in said body, a cap for said body having'a valving ringanchoring portion spaced. radially from said seat to the stem on saidbody, stop means on the stem for limiting movement ofthe can. said caphaving an annular flange spaced radially from said seat and extendingcircumferentially thereof to form a circumferential outlet passageway aflexible valving ring covering said passageway, and

means for clamping the outer marginal edge of the valving ring to saidflange, the inner marginal edge of the valving ring engaging said seatincluding a ring-like body havinga-circumfeb' I ential seat, a caphaving 9. depending flange provide a passageway therebetween, meanssupporting the cap on said body for movement away from the seat, and aflexible valving ring covering said passageway and having its outermargin secured to said anchoring portion of the cap and its innermarginal edge encircling the relief opening and arranged to engage saidseat to close said passageway under weight of said cap and movable fromsaid seat independently of movement of the cap when the pressure in saidpassageway exceeds the pressure acting through the relief opening. I

2. A relief valve of the character described, including a ring-like bodyhaving a circumferential seat encircling a relief opening through saidbody, a cap for said body having a valving ring anchoring portion spacedfrom said seat to provide a passageway therebetween, meanssupporting thecap on said body for movement away from the seat, a flexible valvingring encircling the relief opening in covering relation with saidpassageway, means fixing the outer margin of said ring to said anchoringportion of the cap with its inner marginal edge arranged for support onsaid seat to close said passageway, and a support in said passageway forsupcircling the ring-like body and carried by said and being freelyflexible to disengage said seal;-

responsive to pressure acting on said valving ring through saidpassageway.

4. A relief valve of the character described,

spaced outwardly from said seat and provided with an annular-shoulder, avalving ring engaging the shoulder and overlapping said seat,

a clamping ring carried by the flange to clamp ring carried by theflange to clamp the valving ring against said annular shoulder, a ringenclamping ring in supporting relation with the valving ring, and alever pivotallysupported porting the valving ring circumferentially ofsaid body.

3. A relief valve of the character described.

on said ring-like body and having an arm engageable with said supportingring'to unseat the valving ring.

6. In a relief valve of the character described, a valve body having acircumferential seat, a flexible valving ring, meansclampinglysupporting the outer marginal edge of the valving ring, meansmovably carrying the clamping means on the valve body, and'meansyieldingly retaining the inner marginal edge of the valving ring formovement to and from said seat independently of movementof thesupporting means.

' WILLIAM H. LEBO.

ROY L. SIDESON.

